©BSNHS 2014

Ten phytophagous insects are recorded on Holly. One of the more common is the larvae of the Holly leaf miner fly, Phytomyza ilicus which tunnels in between the leaf layers and is a favourite of Blue tits.

The parasitic wasp Chrysocharis gemma can lay a single egg through the leaf layer direct into the larvae of the Holly leaf miner, and sometimes an even smaller parasitic wasp Pleurotropis amyntas can parasitize the first parasitic wasp.

The larvae of the Holly Blue butterfly Celastrino argiolus feeds on the flowers buds and berries.

This month on the run up to Christmas we take a look at Holly, one of our few native evergreen trees which is a member of the Aquifoliaceae family.

Ilex is a large genus, approximately 400 species, which occur all over the world except in the Artic regions.

Holly trees reach an average height of 15m but it is not uncommon of trees reaching 24m.

Leaves are simple, alternate and waxy, protected by marginal spines, for some reason as trees mature leaves in the upper crown, away from browsing animals, have evolved to become partially or completely absent of spines.

Holly is dioecious having small white flowers with four petals. In early summer these are pollinated by honey bees. It may take 20 years for a tree to flower for the first time and 40 years for trees to produce a full crop of the characteristic red berries.

The berries are mildly poisonous to man but readily eaten by birds and small mammals. Where seeds are allowed it can take 16-18 months for germination to occur.

Holly is often seen standing alone on field boundaries as it was considered unlucky to fell, so many trees have been spared, left to mature.

In Epping Forest there are pure Holly stands which are remnants of medieval Holly woods once wide spread in England, according to Rackham.

Holly fruits

Holly Blue (Celastrina argiolus)

May Tree of the Month - COMMON HOLLY Ilex aquifolium

Holly Leaf Miner (phytomyza ilicus)